cys·​tine | \ ˈsi-ˌstēn How to pronounce cystine (audio) \

Definition of cystine

: a crystalline amino acid C6H12N2O4S2 that is widespread in proteins (such as keratins) and is a major metabolic sulfur source

Examples of cystine in a Sentence

Recent Examples on the Web The lysosomal storage disease is caused by an abnormal buildup of cystine, one of the body's essential amino acids. Giovana Gelhoren,, 23 Apr. 2022 Cystine stones Cystine stones are due to a genetic disorder called cystinuria that causes the amino acid cystine to leak out of the kidneys and into the urine, the NIDDK explains. Carolyn L. Todd, SELF, 12 Nov. 2019 If successful, the treatment will reduce the abnormal buildup of the amino acid cystine, which causes the disease. San Diego Union-Tribune, 26 June 2019 The defect causes the amino acid cystine to accumulate to toxic levels in tissues throughout the body, doing particular damage to the kidneys. Quanta Magazine, 23 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cystine.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of cystine

1843, in the meaning defined above

History and Etymology for cystine

from its discovery in bladder stones

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The first known use of cystine was in 1843

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Cite this Entry

“Cystine.” Dictionary, Merriam-Webster, Accessed 6 Jul. 2022.

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More Definitions for cystine


cys·​tine | \ ˈsis-ˌtēn How to pronounce cystine (audio) \

Medical Definition of cystine

: an amino acid C6H12N2O4S2 that is a dimer of cysteine, is widespread in proteins (as keratins), and is a major metabolic sulfur source

More from Merriam-Webster on cystine

Britannica English: Translation of cystine for Arabic Speakers Encyclopedia article about cystine


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